Essentials of Human Anatomy & Physiology Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Seventh Edition Elaine N. Marieb Chapter 15 The Urinary System

Functions of the Urinary System Slide 15.1a Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Elimination of waste products  Nitrogenous wastes  Toxins  Drugs

Functions of the Urinary System Slide 15.1b Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Regulate aspects of homeostasis  Water balance  Electrolytes  Acid-base balance in the blood  Blood pressure  Red blood cell production  Activation of vitamin D

Organs of the Urinary system Slide 15.2 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Kidneys  Ureters  Urinary bladder  Urethra Figure 15.1a

Location of the Kidneys Slide 15.3 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Against the dorsal body wall  At the level of T 12 to L 3  The right kidney is slightly lower than the left  Attached to ureters, renal blood vessels, and nerves at renal hilus  Atop each kidney is an adrenal gland

Coverings of the Kidneys Slide 15.4 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Renal capsule  Surrounds each kidney  Adipose capsule  Surrounds the kidney  Provides protection to the kidney  Helps keep the kidney in its correct location

Regions of the Kidney Slide 15.5 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Renal cortex – outer region  Renal medulla – inside the cortex  Renal pelvis – inner collecting tube Figure 15.2b

Kidney Structures Slide 15.6 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Medullary pyramids – triangular regions of tissue in the medulla  Renal columns – extensions of cortex- like material inward  Calyces – cup-shaped structures that funnel urine towards the renal pelvis

Blood Flow in the Kidneys Slide 15.7 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Figure 15.2c

Nephrons Slide 15.8 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  The ________________and ____________ units of the kidneys  Responsible for forming __________  Main structures of the nephrons  ________________  _________________

_____________________ Slide 15.9a Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  A specialized ____________ bed  Attached to arterioles on both sides (maintains ________ pressure)  Large ___________ arteriole  Narrow ____________ arteriole Figure 15.3c

Glomerulus Slide 15.9b Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  The glomerulus sits within a _______________ _______________ _ (the first part of the _______________ _______) Figure 15.3c

Renal Tubule Slide Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  _____________ _____________  _____________ _____________ _____________  _____________ _____________ Figure 15.3b

Types of Nephrons Slide 15.11a Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  ______________ nephrons  Located entirely in the cortex  Includes __________nephrons (85%) Figure 15.3a

Types of Nephrons Slide 15.11b Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  _______________nephrons  Found at the boundary of the ___________ and ____________ Figure 15.3a

____________ Capillaries Slide Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Arise from ____________ arteriole of the glomerulus  Normal, _______ pressure capillaries  Attached to a _____________  Cling close to the ____________ tubule  ___________ (reclaim) some substances from __________ tubes

Urine Formation Processes Slide Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  ___________ ___________ Figure 15.4

Filtration Slide Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Nonselective ___________ process  ____________ and ______________ smaller than proteins are forced through capillary walls  ______________ cells cannot pass out to the _____________  __________ is collected in the ___________capsule and leaves via the __________________

Reabsorption Slide Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  The _________________ capillaries reabsorb several materials  Some _________  Glucose  ________________  Ions  Some reabsorption is passive, most is active  Most reabsorption occurs in the _____________convoluted tubule

Materials Not Reabsorbed Slide Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Nitrogenous waste products 1.______________________ 2.______________________ 3.______________________  Excess water

Secretion – Reabsorption in Reverse Slide Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Some materials move from the _________________ capillaries into the _________________ tubules  Hydrogen and potassium ions  Creatinine  Materials left in the ____________________ move toward the ______________

Formation of Urine Slide Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Figure 15.5

Characteristics of Urine Used for Medical Diagnosis Slide Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Colored somewhat yellow due to the pigment ____________ (from the destruction of hemoglobin) and solutes  _____________  Slightly ____________  Normal pH of around ______ (varies 4.5-8)

Ureters Slide Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Slender tubes attaching the ___________ to the ____________  Continuous with the _________________  Enter the ________ aspect of the bladder  Runs behind the ______________  __________ aids gravity in _______transport

_____________ Bladder Slide 15.21a Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Smooth, collapsible, _________ sac  Temporarily stores urine Figure 15.6

Urinary Bladder Slide 15.21b Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  ______________ – three openings  Two from the ______________  One to the ______________ Figure 15.6

Urinary Bladder Wall Slide Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  _____________ layers of smooth muscle (detrusor muscle)  Mucosa made of _____________epithelium  Walls are thick and folded in an empty bladder  Bladder can ___________ significantly without increasing _________pressure

Urethra Slide Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Thin-walled tube that carries urine from the __________ to the ____________of the body by _______________  Release of urine is controlled by two sphincters 1._______________________________ 2._______________________________

Urethra Gender Differences Slide 15.24a Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Length  ______________ – 3–4 cm (1 inch)  _______________ – 20 cm (8 inches)  Location  Females – along wall of the __________  Males – through the ___________ and _____________

Urethra Gender Differences Slide 15.24b Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Function  Females – ___________________  Males – __________________________________ __________________________________

_______________ (Voiding) Slide Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Both sphincter muscles must open to allow voiding  The internal urethral sphincter is relaxed after stretching of the bladder  Activation is from an impulse sent to the spinal cord and then back via the pelvic splanchnic nerves  The external urethral sphincter must be voluntarily relaxed

Maintaining Water Balance Slide Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Normal amount of water in the human body  Young adult females – ___________  Young adult males – ______________  Babies – ___________  Old age – ______________  Water is necessary for many body functions and levels must be maintained

Distribution of Body Fluid Slide Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  ____________ fluid (inside cells)  _____________ _______ fluid (outside cells)  Interstitial fluid  Blood plasma Figure 15.7

The Link Between Water and Salt Slide Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Changes in ___________ balance causes water to move from one compartment to another  Alters ________________________ and __________________  Can impair the activity of cells

Maintaining Water Balance Slide Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Water ____________ must equal water ___________  Sources for water intake 1._______________________________ _______________________________ 2._______________________________ _______________________________  Sources for water output 1.______________________________ 2.______________________________ 3.______________________________ 4.______________________________

Maintaining Water Balance Slide Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Dilute urine is produced if water intake is excessive  Less urine (concentrated) is produced if large amounts of water are lost  Proper concentrations of various electrolytes must be present

Regulation of Water and Electrolyte Reabsorption Slide Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Regulation is primarily by hormones  Antidiuretic hormone (ADH) prevents excessive water loss in urine  Aldosterone regulates sodium ion content of extracellular fluid  Triggered by the rennin-angiotensin mechanism  Cells in the kidneys and hypothalamus are active monitors

Maintaining Water/Electrolyte Balance Slide Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Figure 15.9

Maintaining Acid-Base Balance in Blood Slide 15.33a Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Blood pH must remain between 7.35 and 7.45 to maintain homeostasis  Alkalosis – pH above 7.45  Acidosis – pH below 7.35  Most ions originate as byproducts of cellular metabolism

Maintaining Acid-Base Balance in Blood Slide 15.33b Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Most acid-base balance is maintained by the kidneys  Other acid-base controlling systems  Blood buffers  Respiration

Blood Buffers Slide Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Molecules react to prevent dramatic changes in hydrogen ion (H + ) concentrations  Bind to H + when pH drops  Release H + when pH rises  Three major chemical buffer systems  Bicarbonate buffer system  Phosphate buffer system  Protein buffer system

The Bicarbonate Buffer System Slide Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Mixture of carbonic acid (H 2 CO 3 ) and sodium bicarbonate (NaHCO 3 )  Bicarbonate ions (HCO 3 – ) react with strong acids to change them to weak acids  Carbonic acid dissociates in the presence of a strong base to form a weak base and water

Respiratory System Controls of Acid-Base Balance Slide Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Carbon dioxide in the blood is converted to bicarbonate ion and transported in the plasma  Increases in hydrogen ion concentration produces more carbonic acid  Excess hydrogen ion can be blown off with the release of carbon dioxide from the lungs  Respiratory rate can rise and fall depending on changing blood pH

Renal Mechanisms of Acid-Base Balance Slide Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Excrete bicarbonate ions if needed  Conserve or generate new bicarbonate ions if needed  Urine pH varies from 4.5 to 8.0

Developmental Aspects of the Urinary System Slide 15.38a Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Functional kidneys are developed by the third month  Urinary system of a newborn  Bladder is small  Urine cannot be concentrated

Developmental Aspects of the Urinary System Slide 15.38b Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Control of the voluntary urethral sphincter does not start until age 18 months  Urinary infections are the only common problems before old age

Aging and the Urinary System Slide Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  There is a progressive decline in urinary function  The bladder shrinks with aging  Urinary retention is common in males